The external morphology of four members of the Anopheles gambiae group occurring in southern Africa was studied. Wild-caught larvae or the progeny of wild-caught females were used. Colony material was not used, except for the egg measurements. All life stages of the four species An. gambiae, An. arabiensis, An. quadriannulatus and An. merus were examined and thirteen characters chosen for computer analysis. A multivariate discriminant function analysis was run using all four groups at once and 97% discrimination was obtained.